Brokers' Safeguard

Exile target nonartifact creature you control. It perpetually gains "This creature enters with an additional shield counter on it." Then return that card to the battlefield under its owner's control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6ofsk8bb8jpb1hn739r6e3.